1. Field of the Invention
The present invention relates to automatic composition apparatus and method for automatically composing a piece of music according to various conditions relating to music, and a storage medium that stores an automatic composition program.
2. Prior Art
A known automatic composition apparatus for automatically composing a piece of music according to various conditions relating to music is disclosed in, for example, laid-open Japanese Patent Publication (Kokai) No. 9-50278 and corresponding U.S. Pat. No. 5,736,663.
The automatic composition apparatus disclosed in the above-identified publication or U.S. Patent is adapted to analyze and extract musical features of an already-composed piece of music, and store the results of the analyzing and extracting process as a music template into a performance data memory. The known apparatus enables the user to suitably modify a music template selected from various music templates stored in the memory, to thereby automatically compose a piece of music based on the template that has been modified.
The data contained in the music template includes "emotional fluctuations" set for the whole piece of music, "pitch pattern" set for each phrase, and others, which enable the user to sense the atmosphere of a melody generated according to the music template. The music template also contains data that designate pitches of the first and last syllables of each phrase. When determining pitches of each phrase, therefore, the known apparatus initially determines the first and last pitches of the phrase in question, and then determines the remaining pitches of the phrase in question. If the "pitch pattern" or "data designating the first and last syllables" are not designated for the phrase in question, its pitches are determined according to the "emotional fluctuations" as indicated above.
In the known automatic composition apparatus as described above, the music template contains data represented by abstract or nonobjective expressions such as "emotional fluctuations", and therefore the user cannot tell from the music template what changes of pitches are imparted to a melody that will be generated. Also, since the known apparatus uses such data as "pitch pattern" for each phrase, without taking account of the relationship between those of adjacent phrases, it is difficult for the user to visually grasp changes of pitches over the piece of music as a whole.
In FIG. 6 of the above-identified publication, for example, a "horizontal.fwdarw.downward" curve is set as the "emotional fluctuation" of passage A, whereas "downward.fwdarw.horizontal.fwdarw.upward" arrows are set as the "pitch pattern" of the same passage A. Thus, different changes in the pitch level are obtained based on the two types of data.
In the known automatic composition apparatus as described above, the first and last pitches of each phrase are initially determined based on the "data designating the first and last syllables", and it is therefore difficult for the user to compose a piece of music while considering the whole structure of the music piece. It is possible to compose a piece of music in view of the whole structure of the music piece based on the "emotional fluctuations", if the "pitch pattern" and "data designating the first and last syllables" are not designated for the phrase. If the "pitch pattern" and/or "data designating the first and last syllables" are designated later, however, the resulting pitch changes in the phrase in question may differ from those obtained based on the "emotional fluctuations".
When the user listens to and evaluates a melody of a piece of music composed in the above manner, the known automatic composition apparatus as described above only permits the user to listen to the melody that is played back from the beginning to the end thereof, resulting in an increased time required for evaluation.